1,720,983 research outputs found
Going Beyond Counting First Authors in Author Co-citation Analysis
Get PDFThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
Get PDF“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
Get PDFWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
Dispelling the Myths Behind First-author Citation Counts
Get PDFWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
koamabayili/VECTRON-author-checklist: VECTRON author checklist
No full textWe have done our best to complete the author checklist relating to the use of animals in the hut study. Note that the objective for the hut study was to evaluate the IRS treatment applications for residual efficacy against Anopheles mosquitoes, including the local An. coluzzii mosquito population. Cows were only used to attract mosquitoes into the huts and no tests were carried out directly on the cows. The author checklist is intended for use with studies where experiments are carried out on animals, which is why we have had such difficulty in completing this for the hut study, as many of the questions do not relate to how the cows were used
Missbrauch von Opioidanalgetika: eine Internetrecherche
Get PDFOpioidanalgetika werden weltweit neben ihrem bestimmungsmäßigem Gebrauch auch missbräuchlich verwendet. Hinweise über diesen Missbrauch finden sich unter anderem im Internet in speziellen Chatforen. In der vorgelegten Untersuchung werden durch die Analyse eines Internetdrogenforums folgende Fragen untersucht:
- Welche therapeutisch verordneten Opioide finden in der Missbrauchsszene Verwendung? - Auf welche Weise geschieht dies?
- Gibt es spezifische Unterschiede im Hinblick auf Beschaffung und Beliebtheit zwischen den Präparaten
Einfluss von Minocyclin und Indometacin auf trainingsinduzierte Neurogenese nach experimentellen Schlaganfällen
Get PDFRehabilitative training has been shown to stimulate neurogenesis in the dentate gyrus following stroke and supports hippocampal function. Increasing evidence also indicates that ischemic insults impair neurogenic plasticity. Since inflammatory processes are possibly involved in stroke-induced disturbance of dentate neurogenesis we analyzed whether treatment with anti-inflammatory drugs further promotes training-induced dentate neurogenesis and hippocampal function. Using the photothrombosis model, cortical infarcts were induced in the forelimb and hindlimb sensorimotor cortex of adult rats. After the infarct three groups of animals received daily skilled training of the impaired forepaw and intraperitoneal application of minocycline, indometacin or vehicle during the first two weeks. Another group of control animals received vehicle injections without daily reaching training. Whilst proliferating progenitors were labeled by bromodeoxyuridine injections between day 2-6 post-infarct, dentate neurogenesis was immunocytochemically analyzed 42 days after lesion. Using this approach, we clearly demonstrate that both drugs strongly enhance the effects of skilled reaching training on adult neurogenesis in the dentate gyrus. Compared to animals receiving reaching training alone we detected approximately 60 % more newborn neurons. Assessed against controls with neither training nor drug treatment, post-lesional dentate neurogenesis was more than doubled. Behavioral testing in the Morris water maze from day 35 to day 42 revealed that this increased levels of dentate neurogenesis have marginal effects on spatial learning performance. Combined rehabilitative training and administration of the anti-inflammatory agents minocycline or indometacin significantly promote neurogenesis in the dentate gyrus following stroke, but increased dentate neurogenesis in the context of stroke is not necessarily associated with improved hippocampal performance
Der Einfluss des Chemokinrezeptors CXCR4 auf die Positionierung GABAerger Neurone im Hippocampus der Maus
Get PDFDie Migration GABAerger Neurone im Neocortex wird wesentlich durch das Chemokin CXCL12 und seine Rezeptoren CXCR4 und CXCR7 beeinflusst. Dieser Sachverhalt wurde für den Hippocampus jedoch noch nicht betrachtet. Hier wurde daher die Bedeutung von CXCR4 für die Besiedlung des Hippocampus mit GABAergen Neuronen in Mäusen untersucht. Zuerst wurde die Expression von CXCR4 in GABAergen Neuronen an definierten Entwicklungszeitpunkten analysiert: Hierbei ergab sich für die späte Embryonalphase ein hoher Anteil CXCR4-positiver Interneuronenvorläufer. Dieser nahm mit fortschreitender Entwicklung kontinuierlich ab. Der Zeitraum hoher CXCR4-Expression trat dabei kongruent mit der Interneuronenmigration in den Hippocampus auf. Es wurden konditionale Knockout-Mäuse für CXCR4 in der untersuchten Zellpopulation geschaffen (Cxcr4cKO). Die Untersuchung des Cxcr4cKO erfolgte direkt nach der Geburt (P0) und im adulten Tier (P28-P30). An P0 wurde eine Verminderung GABAerger Vorläufer nachgewiesen, welche umso stärker war, je weiter die betroffene Region von deren Migrationsursprung entfernt lag. Es lässt sich vermuten, dass die GABAergen Neurone ohne CXCR4 nicht in der Lage sind ihren Migrationsweg abzuschließen. In adulten Tieren wurde durch den Cxcr4cKO ebenfalls eine Reduktion GABAerger Neurone hervorgerufen. Die Defekte unterschieden sich jedoch von denen an P0. So lagen an P0 die stärksten Defekte im Gyrus dentatus vor , während an P28 CA2+3 die stärkste Reduktion aufwies. Dies lässt vermuten, dass der Rezeptor sowohl vor- als auch nachgeburtlich die Migration hippokampaler Interneurone beeinflusst. Durch die Analyse von Interneuronen-Subpopulationen ließen sich die Defekte in adulten Tieren größtenteils auf Reduktionen innerhalb der Somatostatin-Subpopulation zurückführen, was eine starke Abhängigkeit der Migration dieser Subpopulation von CXCR4 beweist. Insgesamt zeigt diese Arbeit den deutlichen Einfluss von CXCR4 auf die Besiedlung des Hippocampus mit GABAergen Neuronen
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